Introduction: Testosterone and cortisol, are known as anabolic and catabolic hormones, strongly affected by obesity, and are essential in the management and treatment of obesity. We aim to review the effect of high intensity interval training on testosterone levels, cortisol and T/C ratio in obese and overweight children. Materials and Methods: In this study twenty obese and overweight boys aged 9-12 years, were randomly divided into two groups, the high intensity interval training (HIIT, n=10) and the control (n=10) groups. An explanatory and instructive session was held, in order to familiarize subjects with the training protocol, measurement of maximal aerobic speed and their anthropometric indices. Forty-eight hours after the introductory session, untrained subjects of the intervention group undertook a session of acute high intensity interval training. The intervention group then participated in a training program at 100 to 110% of MAS/3 times per week for 12 weeks. After 12 weeks of regular exercise, the subjects of the intervnention group were trained and another bout of high intensity interval training was conducted to assess the acute effects of exercise on the trained children. Cortisol and testosterone levels in fasting mode were measured in all subjects, before and after sessions of the acute high intensity interval training. The maximal aerobic speed of the subjects was measured using the 20 meter shuttle test. Results: In both training sessions, serum testosterone increased, in the HIIT group, but the increase was not significant in the first session, while it was in the second. In both sessions, cortisol increased significantly. In both acute sessions T/C ratio were significantly decreased. Conclusion: According to these results, high intensity interval training can be manipulated as a method for improving some indicators, related to health promotion in obese and overweight children, and it can be used as a safe, fun and entertaining way to draw their attention to the exercise.